If you need just the original mesh without using displacement map during rendering, take the low poly version, subdivide it a couple of times and use the displacement map in 'displace' modifier (in 3ds max) or similiar in other applications, which will deform your mesh in viewport realtime, so you get the original hipoly mesh. You can use it, or use it as proxy or decimated it etc.

Objects are in their own layer called '_Merged_Buyed'. No part-name confusion when importing. Centered on 0,0,0.